Method of and device for gripping a moving yarn end in textile machines, particularly yarn winding machines

ABSTRACT

A method of and an apparatus for gripping a moving yarn end in textile machines, particularly yarn winding machines having yarn storage magazines which are impositively fed by driven pinch rolls. Upon the breakage of or exhaustion of yarn, the yarn end is automatically gripped in a novel manner. Thereafter, a new yarn end is fed into the apparatus where it meets the old, gripped end in a knotter. After the two ends are tied and knotted, the free ends of the two yarn ends are cut off, the knotted portion of the yarn is released from the knotter, and feeding of the yarn into the yarn storage magazine is resumed.

United States Patent Horatschke et al. Feb. 22, 197 2 [54] METHOD OF AND DEVICE FOR [56] References Cited GRIPPING A MOVING YARN END IN TEXTILE MACHINES, PARTICULARLY UNITED STATES PATENTS YARN WINDING MACHINES 3,160,358 12/1964 Furst ..242/35.5 R 3 I88 125 6/1965 Pesch ..289/2 [72] Inventors. Rudolf Horatschke; Zdenek Holy; Jiri 1 H Premyfl Kostelecky; v i 3,295,775 1/1967 Raasch 8t 8|. ....242/35.5 R j n n f Liberec, Czechoslovakia 3,377,676 4/1968 Ful'St ..289/2 X [73] Assignee: Elltex Zavodny textllnlho strojlrenstvl Primary Examiner Louis Rimrodt generalni redltelstvl, Liberec, Atwmey Anhur O Klein Czechoslovakia [22] Filed: Jan. 23, 1970 ABSTRACT [21] Appl. No.: 5,334 A method of and an apparatus for gripping a moving yarn end A U i i M in textile machines, particularly yarn winding machines having yarn storage magazines which are impositively fed by driven pinch rolls. Upon the breakage of or exhaustion of yarn, the [30] Foreign Application Priority Data yarn end is automatically gripped in a novel manner. Thereafter, a new yarn end is fed into the apparatus where it 1969 czechcrslova'kla 'fl'fl'fi'ff meets the old, gripped end in a knotter. After the two ends are tied and knotted, the free ends of the two yarn ends are cut [52] US. Cl. ..289/1.5, 242/355 R, 289/2 off, the knotted portion of the yarn is released from the [51] Int. Cl. i ..A0ld 59/04 knotter, and feeding of the yarn into the yarn storage [58] Field of Search ..289/1 .5, 2', 242/355, 36, 37 magazine is resumed. v

10 Claims, 7 Drawing Figures METHOD OF AND DEVICE FOR GRIPPING A MOVING YARN END IN TEXTILE MACHINES, PARTICULARLY YARN WINDING MACHINES This invention relates to a method of and a device for gripping a moving yarn end in textile machines, particularly in yarn winding machines, whereby the winding process may be continued upon the breakage of the yarn or the exhaustion thereof.

In hitherto known yarn winding machines, the broken yarn end is wound up completely onto the cross wound bobbin being filled. Only afterwards is the yarn end sucked off by means of a pneumatic device, a certain length of the yarn is unwound from the bobbin by airflow, and such yarn end is carried to a knotter in which the old yarn end and a fresh yarn end are knotted together. The winding process can be continued only after the completion of such knotting operation. It is quite obvious that such necessary interruption of the winding process considerably reduces the rate of production of a winding machine.

There are other hitherto known devices which perform the yarn knotting without interrupting the winding process. In such devices the yarn end being wound on the cross wound bobbin is knotted with a fresh yarn end from a supply cop, the knotting taking place at such a speed that the winding process need not be interrupted, nor need the yarn end he gripped after its breaking or exhaustion. Such device, however, is very intricate and complicated; the response time of the sensor indicating yarn breakage must be relatively short and the working time of the knotter must also be short, since it must knot the yarn moving at a speed equal to the winding speed. A further disadvantage of such device is that it ejects the old not completely unwound cop, which must be used again in the machine. The intricacy of the device and its required accuracy of adjustment considerably reduce its theoretical advantages in efficiency and safety in industry.

It is an object of the present invention to provide a device which at least substantially removes the above disadvantages from yarn knotting or tying devices, particularly those employed in conjunction with winding machines.

The subject matter of the present invention corresponds to the wording of the claims. Further advantages and features of the present invention are set forth in the following specification and shown in accompanying drawings ofa preferred embodiment of the device in such drawings:

FIG. I is a view in perspective of the device in accordance with the present invention with the parts disposed in their ordinary feeding position, that is, with a single yarn end feeding continuously through the device;

FIG. 2 is a view similar to FIG. 1 but with the parts of the device in the position which they assume when the trailing original yarn end has been gripped by the device and the leading fresh yarn end is being fed thereinto;

FIG. 3 is a similar view of the device but with the parts thereof in the new positions which they assume after the two yarn ends have been knotted and the yarn gripping jaws thereof have been opened;

FIG. 4 is a fragmentary view in side elevation of the yarn end gripper and the guide disposed therebelow, the view showing successive positions of the yarn end before it is secured by the gripper;

FIG. 5 is a front view of the yarn end gripper and its control, the view being taken generally from the left in FIG. 4 looking to the right; I

FIG. 6 is a side view of the levers for introducing yarn ends into the knotter, and of the means for controlling such levers; and

FIG. 7 is a view in side elevation of the means for driving the knotter.

Turning now to FIG. 1, the yarn l is withdrawn in a known manner from a supply cop (not shown) through a brake, or other known mechanisms (also not shown). The yarn 1 travels between the opposed feeding rollers 2,3 by means of which the yarn is withdrawn from the cop, the yarn then being guided through a guide 4 disposed above the feeding rollers. It is to be understood that other yarn-feeding means and other yarn-guiding means may be employed, but that the guide must be disposed downstream of the yarn-feeding means, which may also be means such as pneumatic conveyors, etc.

A yarn-gripping mechanism 5 is disposed in alignment with the yarn l but above its normal pass, as shown in FIG. 4. The position of the gripper 5 relative to the normal path of the yarn l is so determined as to enable the yarn end to be gripped by the mechanism 5, upon any yarn breakage, in a self-locking manner. Thus, the yarn-gripping mechanism has a stationary jaw 8 and a similar but opposed and reversed jaw 9 which is movable in a manner to be explained whereby to release the gripped yarn when required. The jaw members 8,9 have gripping edges 6,7, such edges closing an angle greater than 0 and smaller than 45. For normally used yarns, the optimum value of such angle is determined to be from 5 to 10. The value of the angle is greatest at the inlet ends of the edges 6,7 and decreases gradually toward the contact point or zone of the two gripping edges 6,7.

As shown in FIGS. 4 and 5, there is a metal deflector or screening sheet 11 which is disposed between the guide 4 and the feeding rollers 2,3 downstream of the yarn in the direction towards the knotter 10. For clarity of illustration, such deflector plate 11 has been omitted from FIGS. 1, 2 and 3. The guide plate 11 ensures that the yarn end 1, shown in solid lines in FIG. 4, will not be deflected below the guide 4 in the direction towards the knotter 10. To the contrary, the whip or inertia of such yarn end causes it to swing in the direction of the curved arrow T in FIG. 4 to assume the successive positions thereof shown in dash lines. In such last position, the end of the yarn has swung upwardly and has entered between the edges 6,7 7 of the jaws 8,9, thus to be gripped thereby. In the absence of the guardplate 1], the yarn end might surround too much of the guide 4 and by the pull thus imposed upon the yarn end, the yarn would not be thrown in the direction of T and the yarn 1 would run below the gripper 5. For that reason, the metal guard 11 is made in the form of a plane or flat sheet which is arranged substantially parallel to the direction of the yarn as it normally moves from between the feeding rolls 2,3 upwardly to the guide 4. After the yarn end 1 has been thus gripped by the mechanism 5, a span of the yarn between the gripping mechanism and the yarn magazine 16 remains under tension by reason of the pneumatically powered ejector portion at the entering end of the yarn storage magazine.

It is to be understood that the yarn storage magazine 16 is conventional and is not per se a part of the present invention. The magazine 16 and its manner of association with the stop mechanism (not shown) will be better understood upon reference to the copending application of Havlas et al., Ser. No. 33,477, filed Apr. 30, 1970, entitled METHOD OF CONTROLLING THE KNITTING PROCEDURE IN TEX- TILE MACHINES, PARTICULARLY AUTOMATIC WIN D ING MACHINES AND PNEUMATIC CIRCUITS FOR PER- FORMING SAID METHOD," and assigned to the same assignee. Reference should also be had to the copending application of Havlas, Kostelecky and Sedlarik, Ser. No. 2,571, filed Jan. 13, 1970, and entitled DEVICE FOR AUTOMATI- CALLY CONTROLLING THE FEEDING OF YARN INTO YARN SUPPLY MAGAZINES IN TEXTILE MACHINES," assigned to the same assignee.

Continuing with the description of FIG. 1, the yarn I is guided through the guide 4 below the gripper mechanism 5 through the knotting mechanism, consisting of a knotter 10 and feeding members 12. As more particularly shown in FIG. 6, the feeding members 12 are controlled by a cam 13 affixed to a camshaft 14. The levers 12 form the two parallel legs of a generally U-shaped member, the two levers being spaced from each other so as to receive the housing of the knotter l0 therebetween, as shown in FIG. 2. Affixed to the root of the member having the levers l2 thereon is a bellcrank lever which is pivoted at its root-on a horizontal shaft 15 and is pivoted about such shaft against the opposition of a coil tension spring 28 by a cam follower roll journaled on the lower lever of the bellcrank and cooperating with the cam 13. Yarn fed into the yarn storage supply magazine is stored therein in the form of a plug, the yarn being continually withdrawn from the forward end of such plug as a single strand which is thereupon wound upon a cross wound bobbin, as above explained.

The above-described but unillustrated yarn stop motion emits an impulse, upon yarn breakage, in a known manner. Such impulse turns camshaft 14 through one revolution and introduces a fresh yarn end designated 1a that is fed from a further cop (not shown) by the feed rollers 2,3. A known yarnintroducing lever 17 withdraws the yarn end 1a from the feed rollers 2,3 and pulls it across the top of the knotter 10 in the manner shown in FIG. 2. A continued turning of the camshaft 14 and thus of the cam 13 causes the levers 12 to be lowered into the position in FIG. 2 in which they clamp the two yarn ends 1 and 1a within the knotter 10 in position to be tied or knotted thereby as shown in FIG. 2.

The camshaft 14 besides controlling the levers 12 of the knotting magazine, also controls the gripper mechanism (FIG. 5) and the knotter (FIG. 7). Thus a cam 18 affixed to camshaft 14 (FIG. 5) cooperates with a lower, generally horizontal arm 19 of a bellcrank lever which is pivoted upon the shaft 15. The upper end of such bellcrank lever has a yoke 23 which slidingly receives a cross pin 24 on a horizontal rod which is slidably supported in a guiding means 21. The right-hand end of the rod 20 extends through the supporting means 25 for the fixed jaw 8 of the gripper 5, the right-hand end being secured to the movable jaw plate 9 of the gripper by rivets 22 or the like as shown. The movable jaw 9 of the gripper 5 is normally moved into its closed position, wherein it closely confronts the fixed jaw 8, by a coil compression spring 27. When the high point of cam 18 runs under the cam follower on arm 19, however, the movable jaw 9 is moved to the right to open the yarn gripper 5, as shown in FIG. 3. The cam 18 as so disposed upon the camshaft 14 that the jaw 9 is moved into its open position after the knotter 10 has func-.

tioned to tie the two yarn ends 1 and 1a together.

It is to be understood that the jaws 8,9 of the gripper mechanism 5 can be moved apart in various other manners, e.g., the movable jaw 9 may be pivotally mounted to move toward and away from the fixed jaw 8 and the opening motion of the gripper jaw 9 can be performed in various other manners such as pneumatically or electromagnetically.

Also, besides the gripping manner described above, the gripping mechanism may be of the type provided with adhesive yarn-engaging surfaces or it may have gripper jaws with brush surfaces. In both cases, the yarn will be caught up and retained by the yarn-engaging jaws.

In FIG. 7, there is shown the manner in which the knotter 10 is controlled by the camshaft 14. Thus, a cam 29 affixed to the camshaft l4 coacts with a cam follower mounted on the outer free end of a first arm 30 of a two-arm lever pivoted upon the horizontal shaft 15. The lever is constantly urged clockwise (FIG. 7), so that the cam follower remains in contact with the surface of the cam 29, by a coil tension spring 32 as shown. The second arm of the lever is provided at its free end with a ball joint coupling 31 which is connected through a link pivotally connected to the knotter to the operating mechanism of the latter. It will be understood that the cam 29 is so oriented on the camshaft 14 that the knotter functions after the two yarn ends 1 and 1a have been gripped by the levers 12 in the manner shown in FIG. 2.

On both sides of the knotter 10 there are sucking spouts or nozzles 33,34, such spouts serving the purpose of sucking off the cut yarn ends after the knotting of the two ends has been accomplished in the knotter 10. The yarn-cutting means, being conventional, is not illustrated in the drawings. The pneumatic suction lines and other appurtenances are not shown in the accompanying drawings since they are of known, conventional structure. The cleaning of the gripper of the cut yarn ends may be performed in other manners, for example, by brushes or the like.

The above-described device functions as follows:

During normal operation of the machine, the yarn 1 passes continuously from the feeding rollers 2,3 through the guide 4, below the gripper mechanism 5, above the now inoperative knotter 10 and into the magazine 16. The camshaft 14 does not rotate, the jaws 8,9 of the gripper mechanism 5 are closed (FIG. 1). An arrow R indicates the direction of rotation of the feeding rollers 2,3.

Upon yarn breakage or upon some other interruption of feeding of the yarn 1, e.g., upon exhausting the yarn supply of the supply cop, the above-described device continues to operate in the same manner as described until that moment at which the broken yarn passes between the feeding rollers 2,3. After the feeding rollers 2,3 release the yarn end, a section of the yarn l in the area of the guide 4, that is, in front of and behind said guide is swung upwardly in the direction T (FIG. 4) so as to enter between the gripping edges 6,7 of gripper mechanism 5 by the inertia of the yarn end itself, and by the continuing withdrawal of the yarn in the direction S (FIG. 4) into a further mechanism which, in this instance, is a yarn supply magazine 16. A metal guard or screen 11 ensures that the function in FIG. 4 occurs, and that the yarn end does not wrap around the guide 4. At speeds at which the winding machine usually work, the whole procedure described above is performed in a very short period and is comparable to the shooting or injecting of the yarn 1 into the gripper 5. As above described, the metal guard 11 directs the yarn I in such a manner as to eject it in the correct direction. The gripping edges 6,7 of gripper 5 are constituted in the form of a wedge and close an angle between 5 and I0", as described above. This makes the jaws selflocking so that the thus-ejected yarn, once gripped thereby, remains gripped until the jaws are opened.

Yarn breakage usually takes place at the points of highest stresses, i.e., downstream of the feeding rollers 2,3. A yarn breakage stop motion (not shown) is located in that area, such yarn breakage stop motion, upon interruption of yarn l, emitting an impulse to the yarn-introducing lever 17 to grip a fresh yarn and to feed it in the manner shown in FIG. 2, that is, across the top of the knotter. At the same time, the yarn breakage stop motion emits a signal which controls the means for rotating the camshaft 14 so as to cause such shaft to be driven through one revolution.

The rotation of the cam 13 causes the yarns I and la to be fed by the feeding levers 12 into the knotter 10, the yarn I being held between the gripping mechanism 5 and the impositive ejector at the infeeding end of the magazine 16. The direction of movement of the feeding levers 12 in their yarngripping direction is indicated by the arrow U in FIG. 2. The cam 29 then actuates the knotter 10, which knots the two yarns 1 and 1a and cuts off the projecting ends. Finally, the yarn end is released by opening the jaws 8,9 of gripper mechanism 5 by action of cam 18 through the intermediary of the two-arm lever 19 and the slidable rod 20. The cut yarn ends are sucked out of the device by the suction spouts 33,34, in which the direction of airflow is indicated by the arrow B.

After the knotting and cutting off of the yarn ends 1 and 1a, the yarn 1 (FIG. 3) is withdrawn from the magazine 16. Upon breakage of the yarn, it is not necessary to stop the machine when using the device according to the present invention. Before performing the knotting operation, the cross-wound bobbin (not shown) is wound from the yarn I situated in the magazine 16. Under normal operations, the magazine 16 is completed in such manner that the feeding rollers 2,3 feed about 10 to 30 percent yarn more than is withdrawn by the bobbin (not shown). In order to prevent an overfilling of the magazine 16, as above disclosed, such mechanism may be that e.g., of that of Havlas et al. application Ser. No. 33,477 which is assigned to the assignee of the present invention. In such apparatus, a guide is controlled in a known manner by means of an electric impulse during the refilling of the magazine 16, said guide bringing the yarn out of engagement of the feed in rollers 2,3 and thus necessarily controlling the refilling of the magazine 16.

The device according to the present invention can be used i in automatic winding machines, as well as normal winding and rewinding machines as, e.g., warping machines and in other textile machines, in which the yarn moves at a sufficient speed.

Although the invention has been illustrated and described with reference to one preferred embodiment thereof, it is to be understood that it is in no way limited to the details of such a preferred embodiment but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

1. A method of handling a yarn, comprising extending the yarn and impositively pulling the yarn forwardly in the direction of its length over an open guide which deflects the yarn into a salient zone having entering and discharge legs, retarding the yarn upstream of the guide, and upon the breakage or exhaustion of the yarn, gripping the trailing end of the yarn to stop its progress at a location on the convex side of the salient zone when such trailing end leaves its zone of retardation and whips outwardly under inertia and tension forces.

2. A method according to claim 1, comprising disposing a deflector plate within the salient zone generally parallel to the entering leg thereof, whereby to prevent the trailing end of the yarn from winding about the guide.

3. A method according to claim 1, wherein the yarn is gripped by entering between opposed yarn-gripping jaws having gripping surfaces which converge in a direction away from the guide.

4. A method according to claim 1, comprising knotting the gripped trailing end of the first-recited yarn to the leading end of a second yarn fed over the guide from a fresh yarn supply, and thereafter releasing the gripped trailing end of the first yarn.

5. Apparatus for handling a yarn, comprising means for extending the yarn and impositively pulling the yarn forwardly in the direction of its length, means upstream of the impositive yarn-pulling means for tensioning the yarn, an open guide disposed'intermediate the yarn-pulling and the yarn-retarding means for deflecting the yarn into a salient zone having entering and discharge legs, and means for gripping the trailing end of the yarn upon the breakage or the exhaustion of the yarn to stop its progress at a location on the convex side of,the salient zone when such trailing end leaves its zone of retardation and whips outwardly under inertia and tension forces.

6. Apparatus according to claim 5, comprising a deflector plate disposed within the salient zone generally parallel to the entering leg thereof, said plate preventing winding of the trailing end of the yarn about the guide upon release of such end by the yarn-tensioning means.

7. Apparatus according to claim 5, wherein the yarngripping means comprises two gripping jaws having gripping surfaces which converge in a direction away from the guide.

8. Apparatus according to claim 7, wherein the gripping surfaces of the jaws are generally in the form of opposed similar arcs having substantially parallel tangent roots at the crotch between the jaws.

9. Apparatus according to claim 5, comprising means for selectively moving the jaws together, into operative position, and apart to release a gripped yarn end.

10. Apparatus according to claim 5, comprising means for feeding the leading end of a second yarn from a fresh yarn supply over the guide, means for knotting the gripped trailing end of the first-recited yarn to the leading end of the thus fed second yarn, and means for thereafter releasing the gripped trailing end of the first yarn. 

1. A method of handling a yarn, comprising extending the yarn and impositively pulling the yarn forwardly in the direction of its length over an open guide which deflects the yarn into a salient zone having entering and discharge legs, retarding the yarn upstream of the guide, and upon the breakage or exhaustion of the yarn, gripping the trailing end of the yarn to stop its progress at a location on the convex side of the salient zone when such trailing end leaves its zone of retardation and whips outwardly under inertia and tension forces.
 2. A method according to claim 1, comprising disposing a deflector plate within the salient zone generally parallel to the entering leg thereof, whereby to prevent the trailing end of the yarn from winding about the guide.
 3. A method according to claim 1, wherein the yarn is gripped by entering between opposed yarn-gripping jaws having gripping surfaces which converge in a direction away from the guide.
 4. A method according to claim 1, comprising knotting the gripped trailing end of the first-recited yarn to the leading end of a second yarn fed over the guide from a fresh yarn supply, and thereafter releasing the gripped trailing end of the first yarn.
 5. Apparatus for handling a yarn, comprising means for extending the yarn and impositively pulling the yarn forwardly in the direction of its length, means upstream of the impositive yarn-pulling means for tensioning the yarn, an open guide disposed intermediate the yarn-pulling and the yarn-retarding means for deflecting the yarn into a salient zone having entering and discharge legs, and means for gripping the trailing end of the yarn upon the breakage or the exhaustion of the yarn to stop its progress at a location on the convex side of the salient zone when such trailing end leaves its zone of retardation and whips outwardly under inertia and tension forces.
 6. Apparatus according to claim 5, comprising a deflector plate disposed within the salient zone generally parallel to the entering leg thereof, said plate preventing winding of the trailing end of the yarn about the guide upon release of such end by the yarn-tensioning means.
 7. Apparatus according to claim 5, wherein the yarn-gripping means comprises two gripping jaws having gripping surfaces which converge in a direction away from the guide.
 8. Apparatus according to claim 7, wherein the gripping surfaces of the jaws are generally in the form of opposed similar arcs having substantially parallel tangent roots at the crotch between the jaws.
 9. Apparatus according to claim 5, comprising means for selectively moving the jaws together, into operative position, and apart to release a gripped yarn end.
 10. Apparatus according to claim 5, comprising means for feeding the leading end of a second yarn from a fresh yarn supply over the guide, means for knotting the gripped trailing end of the first-recited yarn to the leading end of the thus fed second yarn, and means for thereafter releasing the gripped trailing end of the first yarn. 